Photographic equipment



Jan. 7, 1958 M. J. UPDEGRAFF 2,818,768

' PHOTOGRAPHIC EQUIPMENT Filed March 1G, 1953 3 Sheets-Sheet 1 afg. J'

INVENTOR. MERV IN J. UPUGRAFF.

Jan- 7, 1958 M. J. UPDEGRAFF 2,818,758

PHOTOGRAPHIC EQUIPMENT Filed March 1o, 1955 sheets-sheet 2 mf@ l @2-H4 4I INVEN-TOR. 9,9. IZ MERWN `:.uPnE RAFF Jan- 7, 1958 M. .1. UPDEGRAFF2,818,768

PHOTOGRAPHIC EQUIPMENT Filed March 1G, 1953 5 Sheets-Shee 3 JNVENTOR.MERVIN d'. UPDEGRAFF H15 ATTORNEY United States Patent C PHOTOGRPH'IC'EQUIPMENT Marvin-J. UpdegraifgrvDayton, Ohio.

Application March 10,1953, SerialfNo. 341,393

7y Claimsr. (Clt. 88=.24)Y

This invention relates tov photographic apparatus and more' particularlyto improved apparatus for use wlth miniature cameras.`

It is an object of this invention to provide an improvement over theapparatus shown in applicants earlier Patent' No. 2,574,072;

Another objectofl this invention is to provide a lens supportingattachment having improved means for focusing.

More4 particularly, it is an object of' this invention to provide anarrangement in, which thek apparatus can be easily'and' quickly focusedandl in' which` it is possible to remove, and to accurately return theparts to a given relative relationship for a given focus.

A further object' of this invention is to` provide' an improvedl'ensisupportingL attachment which may bemade` at low cost and whichprovidesA practically unlimitedy focusing adjustment, wherebyV it ispossible to obtain exactly.l the desired compositionor magnificationofthe image.

Another object is toy provide- 'an' improved device for holding the filmoptically flat in the enlargingl operation.

Sti1l= another object is to. provide animprovedA arrangement forcontrolling the color temperature of the lightl usedin varioustypes-offcolor photography.

Other objects andi advantages Ireside in the construction of. parts,`theI combination thereof. andl the mode of? operation, as will becomemoreA apparent fromI the. fol?- lowingdescription.

In the drawings:

Figure l is a pictorial view with parts` brokenl. away,

showingat preferred form. of. lens .supporting attachment;

Figure 2 isa al pictorial view. showing oneV application of.the-.preferredembodiment of this invention;

Figure 3 is an elevational View, with parts broken away, showingthelens-supporting.attachment;

Figure 4 is` a. perspective view. of av composing and focusingviewerattachmentzfor` use with the lens supporting attachment;

Figure 5 is a side elevational. view showingaming which isprovided.withinterrupted thread segments for. use in the lenssupportingattachment;

Figure` is a pictorial view ofthe detent spring;,

Figure 7 is a vertical sectionalview showing the mounting arrangementof; the detent'spring;

Figure 8 is a vertical. sectional view taken substantially on line 8'-8of Figure l0` showing a modied form` of lm holder;

Figure^9`is a vertical sectional view taken on line 9-9 of Figure 10;

Figure lO'vis av bottom View of the film holder shown inFi-gures .8\ and9;

FigureV 11- is a schematicviewl showing means :toraccuratelycontrolling; they color temperature andi intensity of the :light used..in photographing: iand= in; making prints of picturesandfthe like;

FigureI 12. isi-af fragmentary' sectional view taken substantially on.the line'lZl-l-Z of. Figuref7;

2,818,768, Patented Jan. 7, 1958 FigureI 13` is a: frontrview of apreferred modification of VVthis'invention'showing` one'use of theinvention;

Figure; l4 is a perspective view of the' preferred modification of theVinvention withl ther parts assembled in anotherimanner disclosinganother function of the invention.

Figure l5v is another perspective view of the preferred modificationshowing; still another assembly of the parts and another function of theinvention; and

Figure l6'is a sideview ofthel preferred modication disclosingY anotherassembly'arrangement of the parts and anotherfunctionfofthe invention.

rIfhe.lens-supporting,attachment illustrated in the drawings hasbeendesigned. to increase the utility of standard camerasvandparticularlyminiature camerasl and to make it. possible. for camera`usersrto enjoy the increased utility without the necessityy of spending;additional money.

Forpurposesof illustration, al special lens supporting tube.is.showndesigned for use with a` 2 lens which is stand-ard. on nearly all`miniature cameras, although it is obviousy that theinvention is equallyapplicable to other lensrsizes andother types of cameras;

Thelens. of the average miniature camera has far more utility than. most.usersl realize, in that itis not only capable of relatively short.exposure in light of low intensity, but kis also, vhighly corrected,possessingunusual depth of iield at relative apertures and capable ofsharpness of focusl almost beyond.comprehension, with resolving power toa circle of confusion of approximately 1/200 inch in 1expensive lensesand to perhaps 1/000 inch in` higher grade enses.

The lens attachment described herein is designed to take maximumadvantage ofthe capabilities of such. lenses, so as to greatly increasethe utility of the miniature caniera. Thus, the attachment makes itpossible to. use this camera to do close-up table top photography,macrophotography and photomicrography, to copyV all manner of pictures,drawings,` maps, documents, to take pictures ICC of material textures,-flowers,` flies,v insects and myriad.

other. subjects from nature, either in blackA and white. or. in colors.

Referring now to Figures l and 3 of the drawings,

wherein is shown. ay preferred formfof the lens attachment, reference.numerals 10,and. 12 designate. outer and inner telescopicI tubes.wherein. the outer tube 10l is provided with. aremovableend piecer1-1`having a threaded portion 14. which. isy` adapted tof t the threaded.ylens supporting aperture of at standardcamera. The end piece 1I is heldini place relative' to. the tube 10'by means ofa garter type of. detent`spring 13-I whereby iti ispossib'le to quickly assemble and disassemble'the end' piecey 11 relative to the tube.10=

As best showny inf Figures l', 3, 7 and l2', the spring 131smountedfwithinA a groove 15 formed in the outer tube 1'01. The springtliiis` shown in` Figure 7 in a sectional view taken at? theedge of.5 thegroove showing the spring 13y in its locationin the groove 15l Figure l2shows the groove15 and the manner inl which the spring is retainedin thegroove 15'. The groove 15 is partially closed at several points as shownby projections 19. to retain the springv 13 in the groove. The. spring13 is recessed in the groovev 1'5 with only a portion` of the spring13extending out of the groove 15. The yend.cap11` has a iiange 17 whichsnaps through the spring 13, soL as to removably hold. the. cap 1.1. in.place on the: tube 10, as shown in Figure 1.

The inner tuber1-2 isslidably supported within the outer tube 1.0,. asillustrated. The` inner .tube 12 is provided withan4 internal. threaded:portion 16 which is adapted to cooperatev with; complementary threadsprovided on a lens supporting. plate-likering 20E Asshown in Figure l ofthe drawings, the ring 20 is also provided with internal threads whichcooperate with complementary threads on the standard lens assembly orbolder 22.

`For purposes of illustration, a simplied form of lens holder is shown.which comprises an outer member 24 .and a slidable inner lens mountingmember 26 which telescopes within the member 24. The lens assemblv 22 isintended lto represent a, conventional lens assembly of the type whichcomes as standard equipment on many cameras. In order to simplify thisdisclosureJ the details of the lens assembly have not been shown. Thus.the lens assembly of a Leica camera, for example, includes a largernumber of parts including means for adjusting the lens aperture as wellas means for adjusting the focus.

Reference numeral 28 designates means for adjusting the position of themember 26 relative to the member 24. Thus`v by moving the pin 28 withinthe angularly arranged slot 30, the focus of the lens assembly may beadjusted small amount. The focusing made possible by moving the pin 28within the slot 30 merely represents the standard focusing adjustment ofthe miniature camera lens and it is obvious `that such adjustment of thefocus is not enough to enable the average camera to be used for takingpictures of subjects within the close-up field or less than the usualthree feet limitation of focus.

In order to provide for controlled movement of the inner tube 12 withinthe outer tube 10, the inner tube 12 is provided with a series ofcircumferentially extending grooves 34 which serve as detents whichcooperate with the coil spring 36 carried by the adjusting sleeve orfocusing nut 38 which is threaded onto the one end ofthe outer tube 1t!in a manner to be explained more fully hereinafter, The coil spring 36is held within an internal groove 37 provided in the nut 38 as shown.The width of the Igroove 37 slightly narrower at the open edgeq so as toprevent the coil spring 36 from dropping out of the groove when theinner tube 12 is removed from the outer tube 10.

The nut 38 is provided with internal threads or channels 40 whichcooperate with offset projections or interrupted screw thread portions42 provided on the ring 44. The ring 44 is adapted to be welded orotherwise fastened to the outer end of the outer tube 10, as explainedmore fully hereinafter.

Thus, by causing relative rotation between the outer tube 1t! and thenut 38, it is possible to produce telescopic movement of the inner tube12 relative to the outer tube 10. The pitch of the threads 40 ispurposely designed such that the outer 4tube 10 will be moved a distancesubstantially equal to the distance between adjacent grooves 34 in oneor less than one turn of the nut 38 relative to the outer tube 10.Turning of the nut 38 does not cause any endwise movement of the innertube 12 relative to the nut 38, but it does cause relative movementbetween the outer tube and the nut 38.

By virtue of the above described arrangement, it will be noted thatmajor rough adjustments may be made quickly by merely pulling in or outon the inner tube 12. so as to shift the spring 36 from one of thegrooves 34 to another, and the finer adjstments may be obtained byrotating the nut 38 relative to the outer tube 10. One big advantage ofthis arrangement is that after one has made preliminary focusing testsso as to obtain the desired adjustment, it is possible to remove theinner tube 12 from the outer tube 10 and subsequently return the innertube 12 to its original position without the need for again adjustingthe focus.

The ring 44 is in the form of a stamped sheet metal ring which issecured to the end of the outer tube 10. For purposes of illustrationthe ring 44 has been shown provided with four spaced projections 42,whereas in actual practice it would be possible to use some other numberof projections or to provide the outer tube 10 with projecting pinswhich would cooperate with the channels or threads 40 provided in thenut 38. One of several advantages of using the ring 44 is that the outersurface of the tube 10 proper does not need to be threaded or otherwisemarred, thereby leaving the surface available for placing scales orother indicia thereon for use in focusing. Another advantage is that thethickness of the stock from which the tube 10 is cut need not be asgreat as if it were necessary to form threads directly on the tubeitself. The ring 44 may be secured to the tube in any conventionalmanner such as by brazing, soldering, riveting, or the like.

It is desirable yto be able to focus the equipment for a given job `andto thereafter remove the inner tube 12 from within the outer tube 10before actually making the final exposure and to thereafter return theinner tube to its loriginal position relative to the outer tube 10Without the necessity for refocusing. This may be done very convenientlywith the apparatus disclosed herein, as the final focusing operation isaccomplished 'by rotating the nut 38 relative to the outer tube 10, andonce the equipment is properly focused, the inner tube 12 may be readilyremoved and replaced without disturbing the adjustment of the nut 38. Infact, the construction described herein is such that it is possible toaccurately reset all of the parts to a given setting for a givenoperation even after the setting of the adjusting nut 38 has beendisturbed. In order to facilitate resetting the apparatus to a givenfocal adjustment, the adjusting nut 38 and the outer tube 10 have beenprovided with scales 45 `and 46 as shown. The scale 45, which is locatedon the outer surface of the tube 10, includes a first arrow which isdesigned to cooperate with the individual lines on the scale 46 locatedon the nut 38 when the apparatus is used for enlarging, for example.Likewise, the scale 46 on the nut 38 includes la second arrow whichcooperates with the individual lines on the scale 45 when the apparatusis used for reducing. The scales may also be employed in indicating theproper adjustment of the telescopic members when various lenses eachhaving a different focal length are used.

The inner tube 12 is also provided with suitable indicia, such as A, Band C, for the various grooves 34, so that the user can more readilynote a particular setting of the inner tube relative to the outer tubefor a given type of operation. The indicia on the inner tube 12 may, forexample, correspond to various enlargement ratios, such as 1 to 1, l to11/2, 1 to 2, et cetera. By providing these scales, the apparatus may beused for a number of different types of operations, and when it isdesired to repeat a certain type of operation, it is a simple matter toreturn the parts to a given setting merely by noting the relativepositions of the scales for that type of operation.

In Figure 2 of the drawings, a convenient arrangement is shown forconverting a standard camera into one for use in special types ofphotography. Thus, reference numeral S0 designates a table to whichthere is attached a vertical fixture supporting post 52. Referencenumeral 54 designates a light carried by a bracket 56 which isadjustably mounted on the post 52. Reference numeral 58 designates asecond adjustable bracket which is adapted to support the outer tube 10of the lens supporting attachment in any desired position relative to`the table 50. The bracket 58 allows vertical adjustment as Well astilting of the tube 10 relative to the vertical axis of the post 52.Reference numeral 60 designates `a conventional camera in which the lenshas been transferred from its usual mounting to the lower end of thetube 10 and its associated parts have replaced the lens in the camera.The camera lens is attached at the center of inner tube 12. The abovedescribed arrangement is also suitable for use in making enlargements.The light or lamp 54 is capable of swinging around and above an opencamera or other device for use in enlarging. In the particular settingof the parts, as shown in Figure 2, the apparatus is suitable for use inspecialized photography and for use in making enlarged transparenciesfrom 8 or mm.

movie In Figure 4 of thevdrawings, a perspective view is shown ofacomposing and focusing viewer 70 which may serve the purpose of animage viewer used while making enlargements and transparencies. Theviewer 70 is adapted to replace end piece '114 tofit into the endof theouter tube 10. The viewer 7 0 comprises 'a pair of conventionalseparable plates 72 and l74 between which a negative movie film orground glass may be supported in accordance with practice which is nowwell known. The plate 74 is attachedto a cylindrical member 76 which isadapted to be slidable onto the upper end of the tube or on the endpiece 55 of the lamp unit 54, as shown in Figure 2 of the drawings. i lv In referring to Figure 2, it will be noted that the outer diameter ofthe tube 10 is the same as the outer ydiameter of the end portion 55 ofthe lampl unit 54, wherebyy it is possible to interchangeably support(the attachment 70 either on the upper end of the tube 10 or the outerend 55 of the lamp unit 54 merely by sliding the attachment in place onone or the other. y

The apparatusdisclosed herein isl particularly `adaptable for use inspecialized photography in that it makes it possible to support a filmor a series of filmsadjacent the lamp unit and to project the image orimages onto a negative mounted in a conventional'camera placed adjacentthe viewer 70. The viewer 70 may also be used for supporting a filmadjacent the upper end of the tube 10 when it is desired to makeenlargements.

In Figures S through l0 of the drawings, a modified form is shown of amultiple purpose'attachment, somewhat similar to the attachment 70, andonewhich may be used either 4as an image viewer or as av film holder tobe used while making enlargements, transparencies, or for otherspecialized photography. For purposes of illustration, the attachment 80is disclosed as screwed directly to the end piece 82 and comprises apair of condensing lenses 84 and 8,6 which are arranged as shown. Thelens 84 is prevented from moving upwardly by the retainer ring 88,whereas the lens 86'is limited in its downward movement by a fixedglassvplate 90 which is held in place by the retainer ring 92 securedwithin the lower end of the attachment 80. A coil spring 94 is mountedbetween the two condensing lenses and biases them away from one another.

The films or the like which are to be mounted inthis attachment areintroduced into the space between the glass plate 90 and the lens 86through a slot 96. Prior to introducing any film into the slot 96, thecondensing lens 86 is lifted, as shown in Figure 9, by means of a cam 98which is adapted to. be operated by turning the knob 100. By lifting thecondensingv lens 86, as shown in Figure 9, it is easy to insert the filmbetween the lens S6 and the glass plate 90. Upon further turning of theknob 10i), the condensing lens 86 is biased downwardly by the spring 94,so as to firmly position the transparency and to retain the transparencyoptically flat.

Figures 13 through 16 disclose various arrangements and positions of theelements of the preferred modification showing possible applications ofthe preferred modification of the invention. A table 132 retains asupporting post 134 in a vertical position. The supporting post 134- isprovided with a plurality of teeth136for positive adjustment of theheight of a clamp 138 upon the post 134. A bracketltiti is formedintegrally with the clamp 138. A rack 142 is adjustably retained by aclamp 146 upon the bracket 140. A lamp housing 1,41y is rotatablyattached at point 143 to one end of the rack 142. The rack 142 isprovided with teeth 144,A which are adapted to act as positioning andlocking means of the rack 142 upon the bracket 140. The clamp 146isrotatably connected to the bracket 1 40. Due. to, the fact that the.rack 142 is` adiustably retained by the clamp 146, meansv are providedby which the distance of; the lamphousingltl from the bracket may beadjusted. Also, by means of the Aclamp 146, the rack 142 may also beangularly adjusted yupon the bracket 140, thus providing means forangularad'justment of the lamp housing 141 with respect to the bracket140. The lamp housing 141 is rotatably mounted yupon the rack 142. Aclamping ring 148 at the end of the bracket 140 is adapted to adjustablyand rotatably retain various elements of the invention. As disclosed inFigure 13, the preferred modification may be used as a projector. A filmstrip holder 150 is adapted to be mounted and attached upon the multiplepurpose attachment 80. The film strip holder consists of twosubstantially U-shaped portions of wire. The ends of the wire are bent'slightly so as to be inserted through radial orifices formed in thewall surface of the multiple purpose attachment 80. In the applicationas shown in Figure 13, the lens supporting attachment comprising outertube 10 and inner tube 12is attached to the multiple purpose attachment80 and retained by the clamping ring 148 in substantially a horizontalposition. The lens assembly 22v of the camera is thereby employed in theprojection of a picture of the film strip upon a flat surface.

Figure 14 discloses the use of invention as it is employed in the takingof pictures with a conventional camera; 60. The lens attachment havingtubular portions 10 and 12 is mounted upon the bracket 140 and retainedby the clamping ring 148. rl`he camera 60 is threadedly attached to thelens attachment by means of the threaded portion 14. The lamp housing141, with the end lcover 82 removed, is used as a light source. Alswitch 145 located at the small end of the lamp housing 141 is adaptedto control a light source 147 located with the lamp housing 141. Therack 142 is positioned at the proper angle soythat the lamp housing maybe positioned .properly to effectively light the subject of the picturetaken by the camera 60.

Figure 15. discloses the use of the invention as a Isimplified opticalbench arrangement. A viewer attachment 152 is retainedbythe clampingring 148 upon the bracket 140. The viewer attachment, 152 comprises acup-shaped body 154. The body 1,54 is `composed of two sections, 156 and158; The section 158, having the larger diameter, has a support ring fora circular piece of ground glass. The ground glass is retained upon lthesupport ring by the threaded connection` of the inner section 156, theend ofthe inner section rmly holding the glass upon the support ring. Afocusing eye piece 160 lwith lens is threadedly and adjustably mountedin the small end of the innersection 156. When `the viewer 152 ismounted over the end of -the outer tube 10, the ground glass surface ilslocated precisely the distance from the cam-era lens equal to `the focalplane of the camera. Thereby, itis possible to take a picture of apicture slide 162, or a .portion of a picture slide 162, by first makingthe proper adjustments by means of the viewer attachment 152 as shown inFigure 15.. The picture slide 162 isset upon the end of the multiplepurpose attachment 80, as shown, or the film may be removed and heldwithin the multiple purpose attachment S0 as previously described. Thelamp housing 141 is adjustably positioned by means of the rack 142 uponthe bracket 140. The pictureslide 162 may thereby be positioned at theproper distance from the lens in the holder 22. The viewer may then bereplaced by the camera 60 for the photographing of the picture slide 162or a portion of the picture slide 162. The Viewer 152 is inserted in theend of the tubular portion 10 by removal of the end piece 11. When thecamera replaces 4the viewer 152, the end piece 11 is replaced and thecamera attached to threaded portion 14'.

Figure 16 discloses the use of the invention as an enlarger. The partsof the invention are assembled in a manner veryy similar to that inFigure 13, except that thev position of the lam-p housingand of the lenssupporting attachment is shown positioned substantially vertical.However, the lamp housing and ythe lens attachment may be used in anyangular :position during any application of the invention. A means ofdistortion control is yhereby available. The lamp housing 141 with thelens holding attachment may be used at any angle, `whether the inventionis used as a viewer, as a projector, as an enlarger, or as a retainerfor and holder for a camera. It may be readily `understood that thereare a great number of uses of the invention. This invention may beapplied to serve almost any function that may be desired by an owner ofa conventional miniature type of camera.

It is recognized that color photographic processing is more `criticalthan black and white. 4'In addition to exposure and development, thereis the factor of color temperaturc of light that influences all colorsin a color transparency or color print. The light usually considerednormal for color photography is sunlight during the four hours inmidday. An incandescent lamp burning in noon daylight will appear to bevery yellow by contrast, due to its lower color temperature. Lightvaries `greatly in this quality for many reasons. To accommodate thisvariance between daylight and artificial light, `two types of hlm areused, each balanced for its specific use. Additional color correction isavailable by other mean-s, the use of ltcrs singly or in combination, bylight control, exposure of film7 et cetera. A means to achieve lightcontrol often consists of an incandescent lamp in electrical `hookup`with a transformer and rheostat. The transformer increases the linevoltage; for example, the transformer may increase `the line voltagefrom 110 volts to 150 volts. The rheostat is used to regulate the actualamount of current flowing through the bulb or lamp. As the rheostat isadvanced, more `current flows into the lamp, ycausing 4the filament toglow brighter and increasing the color temperature of the light. Toachieve this variable means in the above manner obviously requires atransformer, a rheostat, and usually a voltmeter in combination with thelamp. This equipment is fairly expensive for the purpose it serves andthus limits its availability to persons wishing to do this Work. It isalso limited in capacity to the specific number of lamps it willoperateoften l, 2, 3 or 4 lamps of varying ratings.

My device, generally designated by the reference numeral 99, utilizes anew approach to controllable color temperature. I utilize a `standardl1() volt circuit With a rheostat element 108, a voltmeter 112, anincandescent lamp 114- of, for example, 75 volts, and a push buttonswitch 116, as shown in Figure 1l. The lamp or bulb 114 would bemount-ed in a housing such as 'the housing 54 or 82 describedhereinabove. This improved aryrangement eliminates the need for anexpensive and cumbersome transformer. For all operations, except actualexposure of color film or print material, the bulb is operated at itsnormal brilliance of 75 Volts. Compensation must be made, however, forfluctuations in line voltage. To achieve a given color `temperature forthe photographic function at hand at the line voltage supplied, theactual line voltage is read on `the voltmeter 112. A movable index orscale element 118, which is pivotally mounted at 120 and which isprovided with a pointer 119, is then adjusted to the `correct linevoltage as indicated on the scale 121. The rheostat contacter arm 122 isthen rotated to the desired Kelvin rating given on the scale 118,whereby the bulb 114 will operate at `the exact voltage to produce thecorrect color temperaturc. Light of the desired color temperature is nowavailable by pressing the switch, holding it for `the desired time, andreleasing it to turn the light off. Thus, the lamp burns at thelife-shortening higher color temperatures only for the exact seconds ofexposure time desired.

This color temperature arrangement is likewise advantageous for blackand white photography, in that it provides a fast, simple and highlyaccurate exposure means in addition to the usual, generallyinconvenient, method of changing lens f stops, as in the enlargingprocedure where they are frequently inverted and hard to read, or wheresuch adjustments may disturb focus or alignment.

Although the preferred embodiment of the device has been described, itWill be understood that within the purview of this invention variouschanges may be made in the form, details, proportion and arrangement ofparts, the combination thereof and mode of operation, which generallystated consist in a device capable of carrying out the objects setforth, as disclosed and defined in the appended claims.

Having thus described my invention, I claim:

l. In a device for making color transparencies from movie film and thelike, the combination including a base, a support mounted on said base,a light unit having a tubular end portion, said light unit beingadjustably carried by said support, a film holder having a cylindricalportion slidable over the tubular end portion of said light unit so asto be removably secured to said light unit and rotatable relativethereto, a lens holder, and means for adjustably supporting said lensholder on said support, said supporting means including means foruniversally tilting said lens holder relative to said support wherebyimage distortion may be corrected, said lens holder comprising an outertube provided with a threaded projection at one end thereof adapted tofit the threaded lens supporting aperture of a standard camera, theouter diameter of said tube being such that the tube may receive thecylindrical portion of said film holder for interchangeably supportingsaid lm holder, a sleeve having an internal groove, the other end ofsaid outer tube threadedly engaging said sleeve, au annular coil springrecessed in said internal groove, said sleeve being adjustable on saidouter tube whereby the distance between the threaded projection at oneend of the tube and the coil spring recessed in the sleeve at the otherend of the tube is Variable, and a lens supporting inner tube adapted totelescopically slide Within said outer tube, said inner tube having aplurality of equally spaced annular grooves in the periphery thereof,said annular coil spring providing a releasable detent for engaging saidspaced annular grooves whereby said inner and outer tubes may betelescoped together to a predetermined position.

2. In a device for making color transparencies from movie film and thelike, the combination according to claim 1 wherein the sleeve threadedlyengaging said outer tube is adjustable upon said outer tube throughout adistance substantially equal to the spacing between the annular groovesin the periphery of said inner tube.

3. A lens extension tube assembly adapted for attachment to the lenssupporting aperture of a standard camera or the like, said assemblycomprising, in combination, a rst tube provided with threaded means forengaging the lens supporting aperture of a standard camera, a secondtube adapted to slide telescopically within said first tube and providedwith means for supporting a lens, and means for adjusting the distancefrom said threaded means to said lens supporting means including firstmeans for making a fine adjustment and second means for making a coarseadjustment of said distance, said rst means including an outer sleevethreadedly engaging said first tube at the end thereof opposite saidthreaded means, said sleeve having an internal annular groove, saidsecond means including an annular coil spring seated within said annulargroove, said second tube having a plurality of equally spaced annulargrooves in the periphery thereof adapted to receive said coil spring,said coil spring providing an expansible detent for engaging said spacedannular grooves whereby the distance from said coil spring to said lenssupporting means may be coarsely varied, said adjustable sleeveproviding the means whereby the distance from said threaded portion tosaid coil spring may be finely varied.

radially spaced indicia in the periphery of the other of i saidelements.

6. A lens extension assembly comprising, in combination, an outertubular member provided at one end thereof with a threaded projectionadapted to engage the lens receiving aperture of a camera or the like,an internally threaded sleeve, the other end of said outer tubularmember having an externally threaded portion adapted to receive saidsleeve whereby said sleeve is adjustable upon said outer tubular member,said sleeve having an internal annular groove, an annular coil springseated within said annular groove, the distance between said annularcoil spring and the threaded projection at the other end of said outertubular member being adjustable by rotating said sleeve relative to saidouter tubular member, and an inner tubular member adapted to slidetelescopically within said outer tubular member, said inner tubularmember having means for supporting a lens at one end thereof and aplurality of equally spaced annular grooves in the periphery thereof,said coil spring providing an eXpansible annular detent for engagingsaid annular grooves whereby said inner tubular member is adjustablewithin said outer tubular member such that the distance from saidannular coil spring to said lens supporting means is variable, thearrangement of parts being such that the variation in the distance fromsaid threaded projection to said coil spring is equal substantially tothe spacing between adjacent annular grooves in the periphery of saidinner tubular member.

7. A lm holder for removable attachment to a light unit, said nlm holdercomprising a tubular housing, a pair of condensing lenses mounted withinsaid housing, spring means between said condensing lenses, a filmsupporting plate adjacent one of said condensing lenses whereby a lm maybe held between said plate and said last named condensing lens, andmeans for moving said last named condensing lens away from said plate inopposition to said spring means to facilitate removal and insertion oflms into said film holder, said means comprising a cam for engaging saidlast named condensing lens within said housing, a cam operating knobexternal to said housing, and a shaft penetrating the wall of saidhousing connecting said cam and said cam operating knob.

References Cited in the tile of this patent UNITED STATES PATENTS1,216,696 John Feb. 20, 1917 1,417,326 Jacobson May 23, 1922 1,848,253Howell Mar. 8, 1932 1,930,431 Barnack Oct. 10, 1933 2,061,192 Gaty Nov.17, 1936 2,138,445 Dautzenberg Nov. 29, 1938 2,238,762 Whitaker Apr. 15,1941 2,266,908 Rogers Dec. 23, 1941 2,375,213 Chilton May 8, 19452,381,228 Schmidt Aug. 7, 1945 2,388,842 Hanson Nov. 13, 1945 2,454,422Atkinson Nov. 23, 1948 2,574,072 Updegraff Nov. 6, 1951 2,624,252 JuddJan. 6, 1953

